Wing slot arrangement



April 11, 1944- GP. PEED. JR; ET AL 2,346,326

WING SLOT ARRANGEMENT Filed Sept. 25, 194o G. P. PEED, JR,

8 T. K. PETERSEN.

INVENTORSI.

Patented Apr. 11, 1944 Application September 25, 1349, Seer- ,1 N9: gig-8&1;

12 Claims.

This invention relates broadly to wing slots for aircraft and more particularly to slotted lift modification devices and improved closure means therefor.

In the use of slot creating devices in wings for increasing their lift characteristics and for delaying stall conditions, the entrance or mouth of the slot usually presents an undesirable drag in the normal or aligned attitude of the wing, or its adjacent slot forming elements. This applies to slots which are either of the fixed type entirely within the main airfoil, and the drag results are considerably more noticeable in the variableli ne betwe n the a n el l n mevablei uxiliary ai oil such as a a le n, or flap at the ra lin ed o a v n at the e in edge of the main airfoil. In the more generally used form these slots are disposed laterally, or spanwiseof the wing, and present a wide mouth or entrance at the lower surface WhiQh reduces gradually as it slopes upwardly and rearwardly toa relatively narrow exit on the upper surface at hic the air i ed b th op n sle i directed rearwardly in the line of the airflow adjacent to the upper wing surface.

Generally speaking, the use ,of slot closures, or doors, is wel. k own in theflartand various modificati a e b su g t '.d,.s .d need whe eby the s e a e b e car ied b e the t fi ed irfo r t e mov ble aux li a rioi an ha e been either automatieally, or separately, arranged to close the slot in the high-speed low-dragattie tucie of the wing. The present improvement is, however, rected to a novel arrangement of retractableclosure. elements which has been found to eliminate a number of the difiiculties presented by h r or d vi e a d has at a ned impreved results both in operation andpertorrnance of he in and high t eharae e let csl t is accordin ly a e t e the r een invention t pro ide s te esure d ors whic substantie l ful y .t ee 'th IhQht eI :theele-t in h normal or ali ned at itude .e he w pe elemeht It is a further object to provide slet closure doors presenting a dissimilar configuration .of their upperah lewe t tles-and'art e tletet e e h th area eleed te ethe Ler estima e -imp a rel i e yveomeaetspaee- I A r-furthernbi e 0 the v h eehtzlhvehtlql 91 9- templatesapovel linkage e ien egient r leedily moving t zin reu nected iqleslsrr teleitehte 3 tween extended .slot sealing pesiti on and its retracted or stowed .-position. 111;: i h object'to provide a parallelogram linliage fqr sueh ana tuetme med-melee wh l hehsuree the-pret y t ea object embraces the provisie k such a depieein it hla qe of tone of the glosure a p t ien o the W s lower to. tended position and the pnpesed ieee .gf t 10- u e em nt forms a p rfume ef the de ire 99;}: tour of the forward wall eftnel lqtin its r tteetes position. o

.Other objects and adyantages pf the present invention will become apparent @to one skilled inthe art after reading vor the iollowing .deSC fiRr tion taken together with the accompanying draw The single .figureis across sectional .yiew of a preferred. modification .of the present invention applied to a slotted flap showing the closure means in both its .e tended and retracted .positions and the flap in its aligned and-downwardly extending positions.

-I -n the figuretfe numeral llndicates the trail,- ing portion of an airfoil .of the desired crosssection, the trailing edge of which forms the forward and upward contour of the slot which extends from the region {of the leading portion of its mouth at 26 {and eigtends upw'ardly and r'earwardly with respect to the vwing to its trailmg portion lg whi li terminatesatthe closed-slot e t et 8- the hum r 2 imita e trailing ea tier wh ch ma hieee er et r i the ert e $91 the th r h ei she vi uitable t ht el me 7 he n shown, which term te th fiee'tehe e t the ewewa fslly i ate h -1. v.'e m att esle hdh hi t e lette li 'e leetlihg e e a e e htet e i led in h The closure elements eo e hlar eh p m .h he e wa memleerrli ettle tetwe tuclearance space 26 adjacent the main wing to the similar space 21 adjacent the flap in its up interconnecting link 6 is caused to conform with the positions of the pivots I0 and II which have been determined by the interconnecting link 9, and assisted by the overhanging weight of the rear element the latter is caused to rotate in a clockwise direction in which the links 6 and 9, which were formerly crossed, are caused to be uncrossed or substantially separated. At the same time, the link l6 by virtue of its pivotal connection toward the forward portion of the element 4 tends to maintain its forward or or aligned position. The closure elements aredisposed such that their portionsof greatest depth adjoin or closely oppose each other and their" acute edges extend outwardly and oppositely and is provided with a fixed pivot I5- carried by themain wing section.

The fourth link I6 is pivoted to the forward portion of the element 4 bymeans of the pivot H and is also pivotally mounted at i8 upon the wing. Another, or fifth link [9 also pivotally carried at 20 upon the fixed Wingis pivoted at its outer extremity to the forward closure ele-.

ment 4at the pivot 10 at the intermediate portion of the arms-of the link 9--||l. The third link |3 is also provided with a lug...portion 25 to which is pivotally connected at 22, the piston or movable element 2| of an actuating device 3, the

cylinder portion of which .is pivotally carried upon the fixed wing l at the. pivot 24. The

trailing edge of the main wing section forming the front contour of the slot is provided with an opening 23 through its exterior surface and an adjoining interior space is provided for the retraction or storing of the, folded closure elements as indicated by. the dotted lines in the figure... J

. The extended position of the closure elements 4. and 5 as indicated by the full lines represent its normally closed attitude .in which the flap 2 isin its upper positionaligned with the wing for cruising, or high speed flight conditions. Assuming now that it is desired to extend the flap 2 intoits high lift slot forming positionindicated by the dotted lines, fluid pressure is fed into the lower portion of the actuating cylinder 3 beneath the piston whereby the piston rod 2| is caused to move upwardly for the folding and retraction of the closure assembly. A fluid actuating cylinder has been selected for the preferred modification which may be caused to operate simultaneously by suitable well known interconnection with the flap operating mechanism, but other suitable actuating devices, such as mechanical or cable operating means may be substituted for that shown. As the piston rod 2| moves upwardly the link |3 through its pivotal connection M with the arm l2, lifts the closure assembly'4'5upwardly through the: opening 23 in the slot wall into its retracted or dotted position. The link l9 forming a parallelogram arrangement with the link l3 and being of substantially the same length continues upwardly-in a continual parallel relationship and fixedly determines the positions of the pivot pins l0 and H of the closure elements 4 and '5 respectively.

Asthe linked or articulated closure elements are lifted bodily into the retracted position the retracted position of the forward element.

acutely angled portion in a forward and downwardly extending attitude serving to define the The element 5 having its pivot portions 1 and H now definitely positioned with respect to the link 4, is caused to assume an adjacent position in which the former downwardly facing undersurface portions of the closure elements are now brought together and substantially meet. In this retracted position of the element '5, its former upwardly facing surface 5a has been rotated with the element to a position where it now substantially fills the opening 23 and forms part of the forward wall of the slot, and is aligned and continuous with the slot wall. I

It will be noted that as the piston rod 2| is withdrawn or telescoped within the cylinder 3 the entire piston-cylinder assembly rotates in a clockwise direction about its trunnion, or pivot, 24 following the path of .the pivot 25 into the retracted position of the link I3. In the retracted position of the closure elements 4 and 5 and the extended dotted position of the flap 2 a fully unobstructed slot is presented in which its forward wall has been given the desired optimum profile in which the portion occupied by the sloping face 5a of the element 5 is not dependent upon the form of the lower fiat face of this element. In other words, the lower nearby surface of the wing and the lower surface of the closure elements is usually a fiat plane surface whereas in certain slot shapes the wall extending between the edges of the opening 23 might preferably be curved. This desired curve can 'r'eadily be accomplished by suitably shaping the upper surface 5a of the rear closure element, inasmuch as the flat surface of the element has been retracted into the interior position and is no longer presented to the airflow through the slot. In the closed position of the slot the elements 4 and 5 are aligned to form a wide base triangle of relatively large chordwise dimension, and in the retracted position they are compacted or substantially superimposed. By compacting or folding the closure elements together as they are retracted an opening of but one half the usual length is required to be provided in the wing trailing edge and more readily adapts itself to the desired slot contour. Other advantages and uses of the present invention which will become apparent to those skilled in the art are intended to be embraced within the spirit and scope of this invention as more definitely set forth by the appended claims. a

We claim: I

1. In aircraft construction, a'main airfoil, a trailing edge flap associated with said airfoil in slot forming relationship, the trailing portion of said airfoil forming a wall of said slot, an opening in said wall, a closure comprising a plurality of articulated sections supported from said airfoil, and actuating means for bodily moving and compacting said closure from its extended slotclosing position underlyingthe leading edge of said ifiap through said wall opening t a re! tracted position within the main airfoil.

n 2. .In :a wing system includinga slot, a pair of closure elements for closing the mouth of :said slot, said elements being interconnected by a pair of .links crossed with respect to each other in the slot-closing attitude, an actuating linkage pivotally carried by said wing and pivotally connecting one of said adapted for the bodily retraction of said elements into said wing and means joining said linkage with one of the first said links whereby said closure elements are brought compactly together as they are bodily retracted.

3. In a wing system, a relatively fixed airfoil,- a movable auxiliary airfoil normally aligned with the trailing edge of said fixed airfoil and adapted to form a through slot therebetween in its extended attitude, means for closing the entrance of said slot in the aligned position of said auxiliary airfoil comprising a pair of articulated elements movably supported from said fixed airfoil by parallel links and actuating means for simultaneously compacting and retracting said elements into said fixed airfoil.

4. In a wing system, a relatively fixed airfoil, an auxiliary airfoil normally aligned with the trailing edge of said fixed airfoil and adapted to form a slot therebetween in its extended attitude, means for closing the entrance of said slot in the aligned position of said auxiliary airfoil comprising a pair of articulated elements movably supported from said fixed airfoil by parallel links, and actuating means for simultaneously compacting and retracting said elements into said fixed airfoil, the said closure means comprising a pair of elements interconnected by a pair of links whereby the elements are folded together as they are retracted.

5. In an aircraft wing, a main airfoil, a flap movably associated therewith in slot-forming relationship, a slot closing arrangement comprising a pair of foldable closure elements pivotally interconnected by a pair of links, one of said links having an offset apertured portion, actuating means pivotally engaging said aperture for bodily moving said elements between the extended slotclosing position underlying said airfoil and fiap and its retracted folded position within said Wing, the other link of said pair adapted to limit relative movement of one element with respect to the other as both are moved bodily.

6. In an aircraft wing, a main airfoil, a flap movably associated therewith in slot-forming relationship, a slot closing arrangement comprising a pair of foldable closure elements pivotally interconnected by a pair of links, one of said links having an offset apertured portion, actuating means pivotally engaging said aperture for bodily moving said elements between the extended slotclosing position underlying said airfoil and flap and its retracted folded position within said wing, the other link of said pair adapted to limit relative movement of one element with respect to the other as both are moved bodily, and pivotal connections between one of said elements and said airfoil adapted to definitely position said element with respect to the wing in the said extreme positions.

'7. In an aircraft wing system, a slot-closing arrangement comprising a pair of foldable closure elements pivotally interconnected by a pair of links, one of said links having an offset extension forming a bell-crank, a pair of substantially parallel actuating links pivotally carried by said wing and 'connected'to spaced-pivots on said Sofiset extension, a positioning link pivoted to said airfoil and to one of said closure elements, and means to actuate said parallel links whereby as the closure elements are-retracted bodily from their slot-closing position into their stowed :position within the wing, one of said, elements "51S guided by said positioning :link and the-second said .element is rotated with respect thereto by the joint cooperation of said'first pair of interconnecting links, such that said closure elements are foldably compacted against each other.

8. In an aircraft wing, a slot-closing system comprising dual foldable closure elements, means pivotally interconnecting said elements and including an angular shaped link, actuating means for moving said elements between their unfolded slot-closing and folded slot-opening positions, and means to impart rotation to one of said elements with respect to said angular link during retraction into the wing whereby said interconnecting means imparts rotation to the other of said elements in an opposite direction, to compactly fold said elements together.

9. In a slot-closing system for an aircraft wing, in combination, a pair of bodily movable slotclosing doors, a link member pivotally interconnecting said doors having a third pivotal connection, parallel actuating linkage pivotally engaging said link member at two of its said pivots adapted to bodily move said doors between extended slot-closing and retracted slot-opening positions while maintaining said link member in parallel relationship with said wing, and further linkage means initiated by said actuating linkage adapted to rotate said doors in opposite directions to a compactly folded relationship in the retracted position within the wing.

10. In a slot-closing system for an aircraft wing having a trailing flap, a slot between said wing and said fiap having an opening in a wall thereof, a pair of foldable closure elements adapted in extended position to underlie said wing and fiap and to close said slot, a closure-carrying member pivotally supporting said elements at spaced points, actuating means pivotally associated with said member adapted for its movement between extended and retracted positions,

means pivotally interconnecting said wing with,

one of said elements, and further means pivotally interconnecting said elements with each other at points other than the first said points, whereby in the extended position of said closure assembly the mouth of said slot is substantially closed and retraction of said assembly imparts movement of said closure elements with respect to each other and to said wing to a compactly folded position in which the assembly occupies said slot wall opening and in which a surface of one of said elements completes the contour of the said wall of the opened slot.

11. In a wing having a profile comprised of normally aligned forward and trailing portions disposed for the formation of an aerodynamic slot therebetween, a foldable closure supported from one of said wing portions adapted to be simultaneously extended and unfolded to underlie both said forward and trailing portions in alignment with the undersurface profile of said portions, said closure also adapted to close said slot in said extended position in which it forms a part of said wing profile, and actuating means to simultaneously fold and compact said closure in retracting it to a slot-wall-forming position within said forward wing portion.

tended position in which it forms an aligned part of said exterior profile, and actuating mean to simultaneously fold and compact said closure in retracting it from said extended position to a, position within said wing in which it forms no part of the exterior profile of said slotted wing.

GARLAND P. PEED, JR. THORVALD K. PETERSEN. 

